Cell Adhesion Assessment Reveals a Higher Force per Contact Area on Fibrous Structures Compared to Flat Substrates

The distribution and density of ligands have a determinant role in cell adhesion on planar substrates. At the same time, planar surfaces are nonphysiological for most cells, and cell behavior on planar and topographical surfaces is significantly different, with fibrous structures being the most natural environment for cells. Despite phenomenological examinations, the role of adhesion ligand density in the fibrous scaffold for cell adhesion strength has so far not been assessed. Here, we established a method to measure the amount of cell ligands on biofunctionalized electrospun meshes and planar substrate coatings with the same chemical composition. With this as a basis for systematic comparison and pure polyester as benchmark substrates, we have cultured L929 mouse fibroblasts and measured the adhesion force to surfaces of different chemistry and topography. In every case, having fibrous structures have led to an increased adhesion force per area also at a lower ligand density, which remarks the importance of such structures in a natural extracellular environment. Conversely, cells migrate more on planar surfaces than on the tested fibrous substrates. We thus established a platform to study cell-matrix interactions on different surfaces in a precise and reproducible manner as a new tool to assess and quantify cell-matrix interactions toward 3D scaffolds.